experimental prediction of total thermal resistance of a closed loop eahe for greenhouse cooling system

the design of an earth to air heat exchanger (eahe) requires knowledge of its total thermal resistance (r_tot) for heating and cooling applications. in this research, a 47 m long horizontal, 56 cm nominal diameter u-bend buried galvanized was studied experimental eahe used for the determination and evaluation of thermal properties of heat exchanger. this system was designed and installed in the solar energy institute, ege university, izmir, turkey. based on the experimental results, generalized relationships were developed for predicting of thermal resistance of the heat exchanger.